Asphaltenes are complex heterocyclic molecules that are present in hydrocarbon fluids. Under reservoir conditions asphaltenes are stabilized by resins. During the production asphaltene precipitation can occur due to number of factors such as changes to pressure, temperature, chemical composition of the crude oil and during stimulation operations. Precipitated asphaltene particles may flocculate and deposit on to pipeline surfaces or equipments to cause plugging problems. Precipitated asphaltene particles can also increase hydrocarbon viscosity which may lead to separation problems. In addition precipitated asphaltene particles can cause pore throat plugging which may cause blockages and lead to lower production rates.
In addition to mechanical methods available to mitigate asphaltene related challenges, aromatic solvents can be added to dissolve asphaltenes. However, solubility and of asphaltene in aromatic solvents is very low and improper cleaning can lead to possible slow re-precipitations. To overcome these problems an asphaltene inhibitor or a dispersant is typically added to the production system.